Apparatus for electrolytically treating articles

ABSTRACT

In an apparatus for electrolytically treating metallic parts, a conveyor having an endless belt carries parts through an electrolyte in a tank. The belt includes a plurality of strips of electrically conductive and chemically resistant material which extend laterally across the belt and are spaced longitudinally therealong. Articles to be treated are mounted on the strips. Means are provided for simultaneously maintaining electrical contact with a plurality of the strips for a predetermined distance of travel of the belt. A preferred embodiment includes an anodizing compartment as above described, a dyeing compartment, and a rinsing compartment through which compartments the belt travels in an undulating path. Between the dyeing compartment and the rinsing compartment, means are positioned for withdrawing dye from an anodized article to produce a multi-color pattern on the surface of the article.

United States Patent Jacobs Dec. 10, 1974- APPARATUS FOR ELECTROLYTICALLY TREATING ARTICLES [76] Inventor: John J. Jacobs, 4O Wenona St.,

Depew, NY. 14043 [22] Filed: Feb. 20, 1973 [21] Appl. No.: 334,008

[52] U.S. Cl. 204/203, 204/35 N, 204/202, 204/204, 204/205 [51] Int. Cl. B65g 49/04 [58] Field of Search 204/35 N, 202, 203, 204, 204/205 [56] References Cited UNITED STATES PATENTS 1 ,769,188 7/1930 Rabezzana 204/204 1,950,096 3/1934 Yeager 204/202 2,101,178 12/1937 Hogaboom et a1. 204/203 X 2,127,885 8/1938 Pettit 204/35 N X 3,216,866 11/1965 Orlin 148/6.1 3,391,073 7/1968 Rusch et a1. 204/203 X 3,649,507 3/1972 Welter 204/203 X i A O 8 0 Primary Examiner-John H. Mack Assistant ExaminerW. 1. Solomon ABSTRACT In an apparatus for electrolytically treating metallic parts, a conveyor having an endless belt carries parts through an electrolyte in a tank. The belt includes a plurality of strips of electrically conductive and chemically resistant material which extendlaterally across the belt and are spaced longitudinally therealong. Articles to be treated are mounted on the strips. Means are provided for simultaneously maintaining electrical contact with a plurality of the strips for a predetermined distance of travel of the belt. A preferred embodiment includes an anodizing compartment as above described, a dyeing compartment, and a rinsing compartment through which compartments the belt travels in an undulating path. Between the dyeing compartment and the rinsing compartment, means are positioned for withdrawing dye from an anodized artithe article.

17 Claims, 10 Drawing Figures PATENTE SEC 1 [H974 sum 1 or 2 APPARATUS FOR ELECTROLYTICALLY TREATING ARTICLES BACKGROUND OF THE INVENTION The present invention relates to an apparatus for electrolytically treating metallic parts, especially anodizing aluminum parts. Also, preferred embodiments of the present invention are useful for applying a multicolor pattern to aluminum articles.

In prior art apparatus, the articles to be treated are placed in a metal basket carried on a conveyor above a tank having a plurality of compartments, each containing different treating solutions. The baskets are lowered into a respective compartment for a certain period of time, raised, moved forward, and then lowered into another compartment. This type of apparatus is difficult to operate and thus requires a skilled operator which increases production cost. It also has an inherently low production rate.

In an apparatus described in U.S. Pat. No. 3,391,073 to Rusch et al., the articles to be treated are carried into and out of a tank containing electrolyte by an endless conveyor. The belt of the conveyor is a sheet of titanium or zirconium which conducts the electrical current over its entire length and is connected to a source of direct current-voltage. Although, increased rates of production have resulted, the entire belt is electrically charged during operation. As a result, complex and expensive materials and parts are needed to insulate the belt from the environment. Also, it is often difficult to perform other processes along the path of the belt which do not require an electrically charged belt. Subjecting the entire belt to an electrical charge generates heat which increases the temperature of the solution through which it travels. As a result, refrigerating apparatus is often needed to cool the solutions whereby electrical power consumption of the apparatus is greatly increased.

Heretofore, an apparatus which utilizes an endless conveyor passing directly into the electrolyte and to which a current source can be applied over a predetermined distance of travel of the belt has not been devised.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided an apparatus for electrolytically treating metal articles comprising:

a. a tank for holding a liquid electrolyte;

b. an endless conveyor comprising a resilient belt of nomelectrically conducting material having a plurality of strips of chemically resistant and electrically conductive material extending laterally across the belt, said strips being longitudinally spaced along one side of said belt, a portion of said belt passing through said tank;

c. means for simultaneously maintaining electrical contact with a plurality of said strips over a predetermined distance of travel of said belt within said tank, said electrical contact means being connected to said source of current and voltage.

In a preferred embodiment of the present invention, the above described portion of the tank serves as the anodizing compartment. Other compartments include a dyeing compartment and a rinsing compartment. Between the dyeing compartment and the rinsing compartment means are positioned for withdrawing dye from an anodized article to produce a multi-color pattern on the surface of the article.

The present invention obviates many deficiencies of apparatus of the prior art. With the present invention, it is possible to apply the direct current-voltage over only a portion of the endless conveyor and thus eliminating power losses which hereinbefore have occured. Furthermore, the present invention permits carrying out various processes along the entire length of the conveyor which might be hindered by electrical current or in which the application of current is unnecessary.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of an apparatus of the present invention;

FIG. 2 is a detailed view showing a portion of the anodizing tank in section;

FIG. 3 is a side elevational view in section along 33 of FIG. 2;

FIG. 4 is a detailed view of the belt illustrating the attachment of articles thereto;

FIG. 5 is a detailed view of an article to be treated;

FIG. 6 is a side elevational view in section of the belt;

FIG. 7 is a detailed view of the electrical contact member;

FIG. 8 is a top elevational view along section 8-8 of FIG. 3;

FIG. 9 is a side elevational view along section 9-9 of FIG. 8; and

FIG. 10 is a side elevational view along section 1010 of FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings in more detail, FIG. 1 illustrates a tank 11 having side walls 13 and end walls 15 for holding liquid treating solutions therein. The tank 11 can be of cement block construction with a plastic lining of corrosion resistant material. Partitions 17 are vertical and extend laterally across the tank 1 1 to separate the tank 11 into a plurality of compartments 19. An endless belt 21 is trained about a plurality of rollers 23 for moving the belt 21 in an undulating path into and out of respective compartments 19 in tank 11.

Although the apparatus of the present invention is suited for carrying out a variety of electrolytic processes, it is particularly suited for producing a multicolor pattern on aluminum articles 29. In this latter case, compartments 25 contain solutions such as aluminum cleaner, a rinse, or aluminum brightener. Compartment 27 contains a suitable concentration of an electrolyte 31 such as sulfuric acid. When the articles 29 are connected to the positive terminal of a directcurrent voltage source 33 and the electrolyte solution 31 in the tank 11 is contacted with a negative terminal 35, the articles 29 are anodized when a suitable voltage is applied.

The conveyor system includes a plurality of rollers 23 which are on shafts, each having respective ends journaled for rotation on the sides or walls 13. Within the tank 11, there are two sets of rollers 23. An upper set 37 and a lower set 39 are positioned so that the belt 21 describes an undulating path through the liquid solutions in the compartments l9 and over partitions 17. In the anodizing compartment 27, the upper set of rollers i such as an electric motor 49. The motor 49 has a drive shaft with a pulley thereon connected in driving relationship with the drive roller 47. Articles 29 to be treated are loaded on the top surface of the belt 21 at one end of the tank 11, travel through the various compartments 19 in the tank 11, and are unloaded at the other end of the tank 11.

The endless belt 21 is preferably made of a tough woven fabric which is impregnated with a chemically resistant resin. A plurality of strips 51 extend laterally across the belt 21 and are longitudinally spaced therealong. As illustrated in FIG. 6, the strips 51 are conveniently mounted on the belt 21 by having the ends of each of the strips 51 extend through slots or openings 53 in the belt 21 which are located near the edges of the belt 21. Each of the strips 51 is made of a chemically resistant material, and preferably when the operation to be performed is an anodizing operation, the material should be such that it is not anodized. Titanium or zirconium are ideally suited metals for making the strips 51. The width and length of each of the strips 51 depends on the size of the belt 21 and the operation to be performed. The strips 51 should not be unduly wide so that the belt tends to tear or rip as it follows the path about the rollers 23. It is preferred that the strips 51 extend entirely across the entire width of the belt 21.

As illustrated in FIGS. 4 and 6, each of the strips 51 include a plurality of projections 55 which hold the articles 29 to be treated. The projections 55 are shaped so that they tend to hold the article to be treated in a proper position. The projections 55 can assume a variety of shapes and sizes depending upon the articles 29 to be held. In general, the projections 55 are finger-like extensions that are punched into each of the strips 51 and are urged inwardly when an article 29 is mounted on respective strips 51.

FIGS. 2 and 3 are detailed sectional views of a portion of the conveyor system in the anodizing compartment 27. The endless belt 21 is trained about an upper set of rollers 37 and a lower set of rollers 39 so as to describe a substantially vertical path of the belt 43 in the stretches of belt 21 between the upper set 37 and the lower set 39 of rollers. A support member 57 is positioned over each of the lower set 39 of rollers and between the vertical stretches of the belt 21. The support member 57 which is mounted to one of the side walls 13 of the tank I] in a fixed position is made of an electrically conductive material. The member 57 which is connected to a source of direct current voltage 33 has an elongated shape such as an I-beam. A plurality of flexible members 59 each have one end mounted to the support member 57 with the other end providing electrical contact with the strips 51 on the belt 21. FIG. 7 illustrates in detail a side view of the support member 57 and the attachment of the electrically conducting flexible members 59 thereto. One end of the flexible members 59 is mounted by a bolt to the support member 57 while the other end of each of the flexible members 59 projects outwardly toward the belt and curves near the end of the members 59 in the direction of travel of the belt 21. The curved end part of each of the flexible members 59 provides for a electrical contact with strips 51 on the belt 21 for an increment of movement of the belt 2i. When the strips are mounted on the support members 57 as illustrated in FIG. 7 in an overlapping manner, electrical contact is maintained with a plurality of strips 51 simultaneously and for a predetermined distance of travel of the belt 21. In general, the narrower the strips 51 and the farther apart the strips are mounted on the belt 21, the more flexible members 59 are needed to maintain continuous contact with the strips 51 over a predetermined length of travel of the belt 21.

The flexible members 59 which are stationary with respect to the belt 21 provide for the flow of direct current voltage to the article 29 to be treated. The arrangement of strips 51 on the belt is such that a portion of the belt 21 within the anodizing chamber 27 is contacted for a given distance of travel. As a result, the electricity does not flow through the entire belt 21 but only through the strips 51 which are within the predetermined distance of travel of the belt 21. This arrangement not only permits rapid adjustment of the residence time of the articles within the anodizing compartment so that the degree of anodizing can be carefully controlled but permits adjustment of the amount of current so that a minimum supply can be used.

FlGS. 8 and 9 illustrate in detail the means for providing electrical contact with the strips 51 as the belt 21 travels in a path around the bottom roller 61. The bottom roller 61 includes a coating or strip 63 of electrically conducting material around the periphery thereof. One of the bottommost flexible members 65 contacts the coating 63 which in turn contacts the strips 51 as they come into contact with the bottom roller 61. A vemier control of the time that voltage is applied can be utilized.

A station for applying treating solution to produce a multicolored pattern on anodized aluminum parts is generally indicated at 67 in FIG. 1. FIG. 10 illustrates the station 67 in more detail. At this location, the belt 21 is trained about a roller 69 which can be raised or lowered for raising or lowering the roller 69 which can be used to adjust the tension in the belt 21. As illustrated in FIG. 10, a means is mounted over the belt 21 for dispensing a treating solution on the articles 29 after the belt 21 passes out of the rinsing compartment 71. The means for applying a treating solution which withdraws color from the dyed and anodized aluminum article can be a plurality of dangling strips of cloth material which are saturated with the withdrawing solution. Other means which are not illustrated but are included within the scope of the present invention include nozzles which spray the withdrawing solution under pressure, or a container from which the withdrawing solution will drip onto the articles 29. One factor which determines the degree of color removal is the length of time that the withdrawing solution remains on the articles 29. For this reason, raising the roller 69 will increase the length of time that the withdrawing solution remains on the article prior to the article being rinsed in the rinsing compartment 71. Also, a moveable spray bar may be used to neutralize the withdrawing solution. A lowering of the roller 69 will result in a shorter contact time of the solution with the article and generally results in less color change. By adjusting the roller, the desired degree of color change can be achieved.

While the present invention as been described in conjunction with preferred embodiments thereof, it should be understood that various modifications and changes therein would be obvious to one of ordinary skill in the art. It is intended that the aforementioned description of the preferred embodiments not limit the scope of the invention and that the claims appended hereto include various changes and modifications therein.

What is claimed is:

1. An apparatus for electrolytically treating metal articles comprising:

a. a tank for holding a liquid electrolyte;

b. an endless conveyor comprising a resilient belt of non-electrically conducting material having a plurality of strips of chemically resistant and electrically conductive material extending laterally across the belt, said strips being longitudinally spaced along one side of the belt, a portion of said belt being mounted to pass through said tank and liquid therein;

0. a voltage source; and

d. means for maintaining electrical contact with a plurality of the strips over a predetermined distance of travel of said belt within said tank with said voltage source, said contact means adapted to maintain electrical contact when said strips are immersed in the liquid.

2. An apparatus according to claim 1 wherein said electrical contact means maintains simultaneous contact with a plurality of said strips as said belt moves.

3. An apparatus according to claim 2 wherein said electrical contact means comprises a support member spaced from the surface of said belt and a plurality of flexible members connected to said support member, each flexible member having an end portion for contacting said strips.

4. An apparatus according to claim 3 wherein said flexible members contact said strips whereby electrical contact is maintained with said strips for a predetermined length of travel of said belt.

5. An apparatus according to claim 3 wherein said conveyor includes a plurality of rollers, saidtank includes side and end walls, said rollers being mounted for rotation between the sides of said tank.

6. An apparatus according to claim 5 wherein said rollers include one set of a plurality of rollers spaced above another set of a plurality of rollers, said belt being trained about said rollers to describe an undulating path.

7. An apparatus according to claim 6 wherein said tank includes a plurality of vertical partitions for separating said tank into a plurality of compartments.

8. An apparatus according to claim 7 wherein said belt includes return portion spaced above said tank.

9. An apparatus according to claim 7 wherein said strips each include means for carrying articles to be treated.

10. An apparatus according to claim 7 wherein said compartments include an anodizing compartment, said anodizing compartment including said electrical contact means.

11. An apparatus according to claim 10 wherein said anodizing compartment includes an upper set of rollers and a lower set of rollers, said belt being trained about said rollers in an undulating path so that the stretches of belt between said rollers are substantially vertical.

12. An apparatus according to claim 11 including a plurality .of support members, each support member being vertically aligned and mounted between vertical stretches of said belt and being spaced from the surface of said belt.

13. An apparatus according to claim 12 wherein said flexible members contact said strips whereby electrical contact is maintained with said strips for a predetermined length of travel of said belt.

14. An apparatus according claim 11 wherein said anodizing compartment includes said electrical contact means, said tank includes a dyeing compartment for dyeing anodized articles, and a rinsing compartment.

15. An apparatus according to claim 14 including means for treating articles with a liquid solution after dyeingto produce a multicolor pattern on the part to be treated, said means being located between said dyeing compartment and said rinsing compartment.

16. An apparatus according to claim 15 wherein said conveyor includes a portion passing through said dyeing compartment, another portion positioned above the level of liquid in said dyeing compartment, said treating means includes means for applying a liquid to portions of the surface of the article to produce a multi-color pattern.

17. An apparatus according to claim 16 wherein said applying means includes a plurality of absorbent strips for contacting said articles. 

1. An apparatus for electrolytically treating metal articles comprising: a. a tank for holding a liquid electrolyte; b. an endless conveyor comprising a resilient belt of nonelectrically conducting material having a plurality of strips of chemically resistant and electrically conductive material extending laterally across the belt, said strips being longitudinally spaced along one side of the belt, a portion of said belt being mounted to pass through said tank and liquid therein; c. a voltage source; and d. means for maintaining electrical contact with a plurality of the strips over a pRedetermined distance of travel of said belt within said tank with said voltage source, said contact means adapted to maintain electrical contact when said strips are immersed in the liquid.
 2. An apparatus according to claim 1 wherein said electrical contact means maintains simultaneous contact with a plurality of said strips as said belt moves.
 3. An apparatus according to claim 2 wherein said electrical contact means comprises a support member spaced from the surface of said belt and a plurality of flexible members connected to said support member, each flexible member having an end portion for contacting said strips.
 4. An apparatus according to claim 3 wherein said flexible members contact said strips whereby electrical contact is maintained with said strips for a predetermined length of travel of said belt.
 5. An apparatus according to claim 3 wherein said conveyor includes a plurality of rollers, said tank includes side and end walls, said rollers being mounted for rotation between the sides of said tank.
 6. An apparatus according to claim 5 wherein said rollers include one set of a plurality of rollers spaced above another set of a plurality of rollers, said belt being trained about said rollers to describe an undulating path.
 7. An apparatus according to claim 6 wherein said tank includes a plurality of vertical partitions for separating said tank into a plurality of compartments.
 8. An apparatus according to claim 7 wherein said belt includes return portion spaced above said tank.
 9. An apparatus according to claim 7 wherein said strips each include means for carrying articles to be treated.
 10. An apparatus according to claim 7 wherein said compartments include an anodizing compartment, said anodizing compartment including said electrical contact means.
 11. An apparatus according to claim 10 wherein said anodizing compartment includes an upper set of rollers and a lower set of rollers, said belt being trained about said rollers in an undulating path so that the stretches of belt between said rollers are substantially vertical.
 12. An apparatus according to claim 11 including a plurality of support members, each support member being vertically aligned and mounted between vertical stretches of said belt and being spaced from the surface of said belt.
 13. An apparatus according to claim 12 wherein said flexible members contact said strips whereby electrical contact is maintained with said strips for a predetermined length of travel of said belt.
 14. An apparatus according claim 11 wherein said anodizing compartment includes said electrical contact means, said tank includes a dyeing compartment for dyeing anodized articles, and a rinsing compartment.
 15. An apparatus according to claim 14 including means for treating articles with a liquid solution after dyeing to produce a multicolor pattern on the part to be treated, said means being located between said dyeing compartment and said rinsing compartment.
 16. An apparatus according to claim 15 wherein said conveyor includes a portion passing through said dyeing compartment, another portion positioned above the level of liquid in said dyeing compartment, said treating means includes means for applying a liquid to portions of the surface of the article to produce a multi-color pattern.
 17. An apparatus according to claim 16 wherein said applying means includes a plurality of absorbent strips for contacting said articles. 